Method for preparing hydroxyethyl (METH) acrylate

Abstract

Hydroxyethyl (methyl)acrylate is prepared by a process of a combination of a three-stage tubular reactor and a tower reactor, wherein, firstly, a catalyst, a polymerization inhibitor and (methyl) acrylic acid are mixed until the solids are dissolved, then mixed with a part of ethylene oxide and thereafter enter into a first tubular reactor for a reaction, a reaction liquid flowing out from the first tubular reactor is mixed with a certain amount of ethylene oxide and enters into a second tubular reactor for a reaction, a reaction liquid flowing out from the second tubular reactor is then mixed with a certain amount of ethylene oxide and thereafter enters into a third tubular reactor, and a reaction liquid flowing out from the third tubular reactor is then passed through a stage of an adiabatic tower reactor and aged such that a product liquid is obtained from extraction.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the field of the preparation of hydroxyl acrylates, and specifically, the present invention relates to a method for preparing hydroxyethyl (meth)acrylate and the hydroxyethyl (meth)acrylate product prepared by the method.BACKGROUND ART[0002]Hydroxyethyl (meth)acrylate is a colorless and clear liquid with double functional groups in the molecules, and has a two-stage curing reaction function. It is one of the most valuable special (methyl)acrylates that has been studied mostly around the world. It is mainly used for the preparation of hydroxyl acrylic resins. The polymers of hydroxyethyl (meth)acrylate have special gloss, transparency and weather resistance. In the pharmaceutical industry, the autopolymers of hydroxyethyl methacrylate can be used for dental materials and orthopedics materials as they have no physiological rejections. With the development of the downstream industries, the application of the monomer is still ...

AI Technical Summary

Benefits of technology

The present invention provides a new method for preparing hydroxyethyl (meth)acrylate that solves problems in current processes. The method involves a combination of multi-stage tubular reactors and a tower reactor that independently control reaction conditions to achieve better product quality and higher efficiency. The method allows for a faster reaction time, increased production efficiency, and reduced impurities. The use of a continuous production process simplifies the operation process and improves production efficiency. The method also reduces the risk of explosions and improves safety. Overall, the invention provides a more efficient and safe method for producing high-quality hydroxyethyl (meth)acrylate.

Problems solved by technology

However, the reaction efficiency of the batch tank type reactors are low, and continuous production cannot be processed.

If the processes of stirring tank type reactors are used, the disadvantages are low reaction efficiency, a large amount of gas phase ethylene oxide and by-products such as diesters, monoesters, and static electricity is easy to be generated while the stirring rotating for a long time to easily cause the gas phase EO to explode, thus it is very dangerous; as the reaction progress, the reaction rate is changed, and the adding rate of EO needs to be adjusted at all times, so the operation is complex; and the cost of the investment of the devices are high.

The problems of a very low reactant concentration and a very low reaction rate also exist for the continuous reactors, thus continuous production cannot be processed.

Although continuous production can be achieved by using tubular reactors, if stirring tank type reactors are simply replaced by the tubular reactors, when (meth)acrylic acid and EO are fed, the concentration of the EO is high, explosion will happens easily; the synthesis of hydroxyethyl (meth)acrylate is a strong exothermic reaction, and when the concentration of EO is high, the reaction rate will be too fast, thus too much heat will be released, there will be a risk of temperature runaway; and a too high concentration of EO will result in a further reaction between the generated hydroxyethyl (methyl)acrylate and EO to produce diglycol (meth)acrylate, causing the yield of the product to decrease; furthermore, under the condition of constant temperature, the conversion rate of (meth)acrylic acid and EO at the end of the reaction is low, a lot of (meth)acrylic acid is left, and it will be more difficult for the subsequent separation.

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